FIG. 1 illustrates an exemplary wireless communication system. Referring to FIG. 1, a wireless communication system includes a plurality of base stations 110 and a plurality of user equipments (or user terminals) 120. The wireless communication system 100 may include a homogeneous network or a heterogeneous network. Herein, the heterogeneous network refers to a network having different network entities, such as an IEEE (Institute of Electrical and Electronics Engineers) 802.16e system, an IEEE 802.16m system, a 3GPP LTE (Long Term Evolution) system, a WIFI system, and so on, co-existing therein. Furthermore, the homogeneous network may be categorized as a macro cell, a Femto cell, a Pico cell, a relay station, and so on. A base station generally corresponds to a fixed station that communicates with a user equipment. Herein, each base station (110a, 110b, and 110c) provides a service to specific geological regions (102a, 102b, and 102c). In order to enhance the system performance, the specific geological region may be segmented to a plurality of smaller regions (104a, 104b, and 104c). Each of the smaller regions may be referred to as a cell, a sector, or a segment. In case of the IEEE (Institute of Electrical and Electronics Engineers) 802.16 system, a cell identifier (or cell identity) is assigned with respect to the entire system. Conversely, a sector or segment identifier is assigned with respect to the specific region to which each base station provides the corresponding service. Herein, the sector or segment identifier is given a value of 0 to 2. The user equipment 120 is generally distributed in the wireless communication system, and, herein, the user equipment 120 may be fixed or mobile. Each user equipment may communicate with one or more base stations via uplink and downlink at a random instant. The base station and the user equipment may communicate with one another by using a Frequency Division Multiple Access (FDMA), a Time Division Multiple Access (TDMA), a Code Division Multiple Access (CDMA), a Single Carrier-FDMA (SC-FDMA), a Multi Carrier-FDMA (MC-FDMA), an Orthogonal Frequency Division Multiple Access (OFDMA), or by using a combination of two or more of the above-mentioned access methods. In the description of the present invention, an uplink refers to a communication link from the user equipment to the base station, and a downlink refers to a communication link from the base station to the user equipment.